Periphery questions and honest answers

Yes to both. Scanning, connecting, reading and writing characteristics, UUID names and the Locate screen all run over Bluetooth on the device. The only things that go online are the ads in the free version and App Store purchases or restores.

Any Bluetooth Low Energy device that is advertising nearby. The list shows its name (or Unknown plus the start of its identifier when it has none), a short identifier and its signal strength in dBm. The raw advertisement payload is not shown in the list. Once you tap a device, Periphery connects and shows its services and characteristics, which you can read, write and subscribe to.

It can tell you whether they are advertising and how strong the signal is, and the Locate screen tells you whether you are getting warmer or colder as you walk. It cannot show a map or a direction, because Bluetooth signal strength has no bearing. Many earbuds only advertise when they are out of the case or the case is open, so a closed case with flat batteries may not appear at all.

No. iOS only exposes Bluetooth Low Energy to apps. Devices that only speak classic Bluetooth, such as many older car kits and headsets, cannot be seen by Periphery or by any other App Store app.

That is iOS and the device, not the app. iOS never gives apps a device's hardware MAC address; it shows an identifier it generates. Many phones, trackers and earbuds also rotate their private Bluetooth address for privacy, so the same device can reappear as a new entry after a while.

Yes. Periphery is a single app for iPhone and iPad and needs iOS 17 or later. There is no Mac, Apple Watch or Android version.

The free version counts every scan you start over the life of the app, not per day, and the count never resets on its own. Once your third scan has started, opening a device or starting a new scan asks for Pro. You can watch a short ad on the upgrade screen to get one extra scan instead.

Unlimited scans and connections, no ads, and session logging. With Pro, every read, write and notification during a connection is saved in the Logs tab, and any session can be shared as plain text with Export. Pro is available as weekly, monthly or yearly subscriptions or as a one-time lifetime purchase.

No. Logging and export are Pro features. Without Pro, no session is ever recorded, so the Logs tab stays empty and there is nothing to export. The scan list itself is never saved; it starts fresh every time you start a scan.

It is an estimate, not a measurement. Periphery converts signal strength to distance with a standard path-loss formula that assumes -59 dBm at 1 metre, so a reading of -70 dBm shows about 3.5 m. Walls, your body, a pocket or a case can move the reading by several metres, so use it to tell warmer from colder.

Bluetooth signal strength naturally fluctuates by several dBm from one packet to the next. The Locate screen smooths the readings so the gauge moves steadily, but it still reacts to you turning around or putting a hand over the phone.

No. Periphery never asks for Location permission. Everything it knows about distance comes from the strength of the Bluetooth signal it receives.

It can try to connect to any device that accepts connections. Devices that only broadcast, or that are already busy with another phone, may refuse, and Periphery gives up after 10 seconds and shows the error. Characteristics that need pairing or encryption may ask iOS to pair first.

Writing sends bytes straight to the device, and what those bytes do is up to its firmware. Only write to devices you own or are testing, and only values you understand. Periphery shows how many bytes will be sent before you tap Send, and it refuses input that is not valid hexadecimal.

Sometimes. After connecting, Periphery compares the device's services with a short built-in list of known profiles and chips, such as Nordic UART, ESP32, Xiaomi, Shelly, heart rate, HID and cycling sensors. Anything else is labelled Standard BLE Device or Custom BLE Device, and you judge it from its UUIDs and values.

The free version shows a banner, an ad card every few rows in the scan list, an occasional full-screen ad when opening the inspector and an ad when you come back to the app after a long break. Any Periphery Pro purchase removes all of them.

Open Settings in the app and tap Restore Purchases, signed in with the same Apple Account you bought Pro with. The same button is also on the upgrade screen.